This is a subjective question that would be very specific to the person responding. With this in mind, I do feel some disappointment at not having carried out my plans as expected. However, having life experience in organizing events and other projects, I have learned that things rarely ever go as planned. Thus, it does not cause too much frustration. Stress occurs in life when you expect A and instead get B.
People who are new to event planning and operations will stress out about changes. For the most part, people who attend won't even know that something went wrong. In some cases, when something does go wrong, as long as it's communicated, it is not as bad. The advantage of those things that go unnoticed is that the attendees don't know what A looks like, so if they get B, they won't know the difference.
Life itself is one long, extended event. Some parts follow the plan. Some parts do not. You shoot for A and get B. Sometimes B is actually better than A. Sometimes B is just as good as A. Sometimes B serves as experience to help you achieve A the next time around.
I think the worst feeling, one that could be frustrating, is that you have a plan and then sabotage yourself in achieving it. This can happen by not preparing yourself sufficiently, having bad habits that interfere with achieving your plans, or even lacking focus on your plan. This last one is especially tricky. We often have too many plans at once. You CAN carry out all your plans, just not all at once. Giving each plan its necessary attention to the exclusion of other plans increases your chances of success.
Occasionally, unexpected circumstances crop up that derail your plans. You simply put things on hold and come back later. It really is out of your control when circumstances do not permit. Forcing the issue will not give you results, only cause frustration.
In business, unexpected events are often dealt with using insurance or other risk management. You think about what could derail your plan and have a general idea how you will deal with them if they do occur. Disaster planning and resilience are important for businesses to get through the worst circumstances. Sometimes it physical. Sometimes it's contractual.
In your personal life, it pays to think through threats to your plans and, drumroll please, have plans to get yourself back on track if something unexpected occurs. So, perhaps the frustration is with not having a plan for dealing with threats to your main plan. With contingency plans in place, the unexpected can be dealt with along the way so that you can continue your main plan with minimal loss of time. In this case, the unexpected is already part of the plan.